This invention relates to multiple element, cylindrical, metallized film wound capacitors, and more particularly to such capacitors and the method of making the same which utilize at least one very small integrally wound element to which electrical connections must be made.
In U.S. Pat. No. 3,921,041 entitled "Dual Capacitor" by the inventor of the present invention, there is disclosed a method for winding a dual capacitor utilizing two metallized films. After winding has progressed through a predetermined number of turns for one of the capacitors, the metallized layer of one of the films is removed over a selected area and an insulating sheet or strip having a length sufficient to encircle the capacitor at least once is inserted between the layers to extend beyond one end of the capacitor and to separate the portions of the metallized film which have been removed. The winding is then completed and each end of the wound section is metal plated. Leads are secured to the plated ends from which the insulating sheet or strip extends, one lead being placed within, and the other without, the insulating barrier. This has been proved to be a very effective method of winding a multiple element capacitor. There is a problem, however, when the inner capacitor section is extremely small, for example, 0.15 to 0.25 inch diameter for making capacitors of the size of approximately 0.05 microfarad. Because of the small number of turns, it is difficult to make lead connections by metal flame spraying the end of the section of the small capacitor and soldering an electrical lead thereto inside a barrier. Furthermore, great care must be provided in selectively removing the metallized layer in order to provide the proper plate size in order to obtain a 0.05 microfarad capacitor.